The determination of the electronic structure, potential surfaces, and dynamics of molecules can be an important element in achieving an understanding of their biological function. It is the general purpose of the research proposed here to use theoretical techniques for the elucidation of the properties of molecules of biological importance. For certain molecules (e.g., the visual pigments) the available information suggests that electronic changes (such as those involved in excitation, charge transfer, conformational alterations, etc.) may be essential for the biological activity. We propose to do quantum mechanical calculations for such systems to provide a knowledge of the essential aspects of their electronic structure. For other molecules (many proteins), the electronic structure is relatively constant and empirical potential functions can be used to study the energy and forces as a unction of conformation. We propose to examine certain proteins and protein complexes and to utilize classical mechanical techniques for determining their dynamical behavior.